Lysergic acid diethylamide (LSD), or acid as it’s commonly known, is a potent, long-lasting psychoactive drug. In part, it’s derived from a fungus that grows on rye and other grains.

The synthetic drug has a chemical structure similar to serotonin, a “feel-good” chemical in your brain. When acid molecules land on serotonin receptors, they cause LSD’s well-known visual and physical effects. This includes color and shape distortions, hallucinations, and other psychedelic effects.

LSD molecules bind more strongly to serotonin receptors than serotonin itself. When the molecules nestle into the receptor pockets, amino acids within the receptor put a “lid” over the molecules. This traps the molecules in place.

The drug’s effects won’t begin to fade until the molecules are knocked off or come loose from the serotonin receptor. This can take anywhere from 6 to 15 hours. It all depends on the potency of the drug, your size, and any other medications you might be taking.

Acid is a colorless, odorless liquid. For consumption, an acid manufacturer typically drips the liquid onto absorbent, colorful paper squares called blotter papers. Each blotter paper can have several “tabs,” and one tab is usually enough to induce a trip.

LSD is also sometimes sold as capsules, pills, or sugar cubes. In each form, the LSD is diluted with other chemicals or products. Potency for each LSD product varies, and there’s virtually no way to know how much LSD is in any form you take.

LSD is considered a safe and nontoxic drug when taken at standard doses. LSD toxicity, or death from LSD, is rare.

You’re more likely to have a “bad trip” — a distressing psychedelic episode — than you are to experience physical harm.

For most people, a dose of 1 to 3 micrograms per kilogram of body weight is enough to produce a moderate trip.

If you haven’t used acid before, starting with a smaller dose may be a safer way to determine how your body handles the drug. Heavy doses of LSD can create intense highs that make you uncomfortable or nauseous.

Without chemical testing, it’s impossible to know how much LSD is in any product you choose to take. However, a quarter-inch tab from a blotter paper typically contains 30 to 100 micrograms.

An LSD gelatin, or “window pane,” may contain slightly more acid per piece. They usually contain anywhere from 50 to 150 micrograms.

Liquid LSD is very potent. You should avoid taking it directly unless you know how diluted it is.

LSD is a psychoactive drug. The effects of the drugs often alter your perception of your environment, your body, your mood, and your thoughts. What’s real and what’s imagined becomes less clear during an acid trip.

The effects of an acid trip can be felt in two ways: how acid affects your body and how acid affects your brain.

Effects on your brain/perception

LSD creates powerful hallucinogenic effects. Your senses are heightened during a trip, and everything in your environment may feel amplified.

During an acid trip, you may see:

brighter colors

morphing shapes

trails behind objects

unusual patterns

“noisy” colors

LSD can also amplify your mood. If you take acid when you’re feeling good, you may feel more relaxed, happy, or content. You may also become exuberant and joyful.

If you take acid while you’re upset or angry, you may grow more upset or frustrated during the trip. Take your current mood into account before you decide to trip.

Little research about the long-term effects or risks of LSD is available, but LSD is generally considered safe and well-tolerated. The risk of death and severe consequences is low.

However, negative side effects are possible, and the use of LSD does carry some risks:

Bad trip. During a bad acid trip, you may feel scared and confused. You may experience hallucinations that leave you terrified and distraught. Bad trips can last as long as good ones, and there’s no way to stop the trip once it begins. You can expect the effects to linger for up to 24 hours after the bad trip begins.

Tolerance. Tolerance to acid develops quickly. Repeated acid use may require larger doses in order to reach the same effect. However, this tolerance is short-lived. If you stop using acid for a period of time, you’ll lower your threshold for what’s necessary to trip.

Flashbacks.Hallucinogen persisting perception disorder is rare. It causes sensory disturbances similar to what you experienced during a trip. These “flashbacks” can occur days, weeks, or even months after your last acid trip.

Psychotic issues. LSD use may trigger schizophrenia in people who are predisposed to the condition. However, this connection remains unclear.

Legal troubles. In the 1960s, U.S. state and federal governments declared LSD an illegal, controlled substance. It remains such today. That means if you are caught with the drug, you may face prison time, fines, or probation.

If you’re interested in trying LSD, be sure to know your risks — both physical and legal —before you seek out the drug. Although many people tolerate acid trips well, bad trips and other negative side effects can happen.

If you decide to try acid, ask a friend to stay with you during your trip. They should stay sober until you fully come down from the drug. If you begin to experience any negative effects, they can help keep you safe and reassured of your reality.

You should also let your doctor know if you have taken or will continue to take LSD. Acid can interfere with some prescription drugs, including antidepressants, so it’s important to be honest about your recreational activity.